It is known to provide apparatus which captures images of a primary user at one location interacting with a document or other object. The captured images can subsequently be displayed at a remote site as an image of the document/object and the interaction of the primary user with the document. To be truly useful such apparatus should provide real time images (or almost real time) of the interaction and the document, although the images may be recorded for subsequent transmission to the remote user.
For document sharing with interaction specialist electronic sharing tools have been developed which support the sharing of electronic documents between users across a network. Each user is provided with a computer which is connected to the network and includes a display upon which an image of the document can be presented. It is useful to enable a user to interact with the document and in many applications (such as Netmeeting® by Microsoft Corporation of Redmond Drive, Seattle, Wash., USA) the user can interact with the images by moving a cursor around the screen. The movement of the cursor is then displayed on every users screen at the same time.
The ability to interact with an electronic document through the use of a pointer such as a mouse is difficult and some users do not find it a natural way to interact with a document. The interaction can be very stilted and it does not offer the range of interactions possible when co-present. Working with a hard copy or an original of a document is also easier for many users than interacting with an image on a screen.
Video conferencing, as a genuine alternative, allows a user at a remote site to see how a primary user interacts with an object. A user can then interact with the document and the interaction will also be caught on camera provided it is in the field of view of the camera. The stream of images are then either stored on a tape or the like for time-shifted viewing or perhaps sent across a network to the remote user where the images are reproduced on a screen. The remote user can then see the areas of the document that the user is pointing to.
In order to provide sufficient resolution for a document to be readable by a remote user and also to cover the area of a typical A4 document, the amount of storage space needed and/or the bandwidth needed for the connection to the remote user must be very high. This can be ameliorated by reducing the capture rate of the camera, although the resulting jerky images then make the interaction difficult to follow.